A catheter is a typical example of an elongate flexible medical member to be introduced into the body of a patient. Such a catheter is introduced into a tubular anatomical opening of a patient, and therefore must be relatively flexible. The catheter tip must also reach a patient's internal organ, so therefore must be relatively elongated.
Manual insertion of a catheter, or more generally a flexible elongate medical member, into the body of a patient, for example into a tubular anatomical opening, is a relatively standard medical procedure. However, as this procedure is generally monitored by X-rays, the practitioner is exposed to a certain amount of radiation when performing such insertions repeatedly.
To reduce the risks to the practitioner related to repeated irradiation by X-rays, efforts have been made to automate such insertion so that this procedure can be carried out by a robot controlled by the practitioner remotely, still under X-ray guidance but from a room not exposed to the radiation. Such automation is complex, as retaining a grip on the catheter is problematic because it is bathed in preservative liquid such as normal saline solution and must remain sterile. In addition, it must be possible to alternate between rotational and translational movements of the catheter in a completely reliable manner, to enable the practitioner to conduct an examination.
Finally, it is also desirable for such a drive module to work with catheters of different diameters or with other elongate flexible medical members, such as a guide, of smaller diameter than a catheter and generally placed inside the catheter to serve as a guide for the catheter to slide on, or an interventional catheter, also arranged inside the catheter, having a tip providing some medical function such as a surgical tool (clamp, balloon, etc.).
There is therefore a need to develop drive modules that can reliably grip a catheter or other flexible elongate medical members and reliably drive their translational and rotational movements, and that are able to adapt to the varying dimensions of such members.
Recently, a drive system for managing both the translation and rotation of the catheter was proposed in document U.S. Pat. No. 7,917,310. In the system according to this document, the catheter is carried and retained on a plate rotatably mounted on a base to impart rotational motion to the catheter. The plate itself is provided with a mechanism to impart linear motion to the catheter, as well as a biasing wheel associated with an adjustment knob for adapting the drive mechanism to different catheter diameters. The drive system according to this document makes use of external motors, permanently fixed to the frame and associated with systems for transferring linear and rotational motion to the catheter.
However, in the system according to this document, adjustment of the biasing wheel must necessarily be done manually by the practitioner, in an area that may be difficult to access, and located in a room subject to X-ray irradiation, which is not satisfactory in view of the resulting problems outlined above.
Therefore, a need exists to develop catheter drive modules in which adaptation to the procedures concerned can be performed remotely by the practitioner when he or she is located in a room not exposed to X-rays.
The present invention is intended to overcome some or all of these disadvantages.